As a result, I always try to get every last bit of oil paint out of every tube! One tool that I use to help me get that paint out is my tube wringer:
I've had this wringer for something like 30 years now and it's still going strong! I once bought a new, plastic version to use with my acrylic paints and it fell apart in less than a year. The metal wringers are a great investment!
As useful as they are, they can only wring a paint of tube so far. They get up to the thicker circular metal around the cap and that's about as much as they can do, but I know there is still good paint in there, so out come the back up tools: Pliers and a small square of plastic canvas!
Oil paint tubes can be cut by the edges of the pliers, but with the addition of a small square of plastic canvas (cardboard will work too), I can squeeze every last bit of paint out of my tubes!
Years ago I used to take the left over paint at the end of a painting session and make abstracts with the paint on canvas boards. The idea was that the canvas boards would be given Velcro strips on the back and the smaller canvas boards could then be grouped and regrouped on some larger backing. I used to have about a dozen of these abstracts on a bulletin board in my studio. Somewhere in my studio there is a large pile of abstract canvas boards. It always struck me as ironic that in the crazy world of art there seemed to be a real possibility that those left over paint abstracts could end up being considered more important than the paintings into which I invest so much work.